ASSIGNMENT 2 FOR MARKETING RESEARCH
Submitted by Cdr Devraj Patel
CASE BASED ON YASEER RESTAURANT
Question 1: What type of sampling design is being used in this case? Critically
examine it and explain whether it could lead to any sampling frame error.
Answer.
The sampling design being used in this case is a stratified sampling
design. Yaseer plans to survey 1,000 households in Ramveerpur, and he intends to
contact every 100th household within each locality to ask about their eating
preferences. The population is stratified into different communities (Muslims, Sikhs,
Jains, and Hindus) based on their religious affiliations, and within each community, he
plans to systematically sample every 100th household.
While stratified sampling can provide more accurate information about different
subgroups within the population, there is a potential issue with the sampling frame in
this case. The sampling frame error arises because the strata are defined based on the
religious composition of the town, and it is assumed that all members of a particular
religious group have the same eating preferences. However, within each religious
group, individual preferences can vary significantly. For example, not all Muslims may
be non-vegetarian, and not all Jains may be vegetarian. This assumption can lead to a
biased estimation of eating preferences within each stratum.
Question 2: Suggest an alternative sampling design. Also indicate how the process
must be carried out to execute your suggested design.
Answer:
A more accurate and representative sampling design would be stratified
random sampling with proportional allocation. Here's how the process should be carried
out:(a)
Begin by dividing the town's population into the four strata (Muslims,
Sikhs, Jains, and Hindus) based on their religious affiliations, just as in the
original plan.
(b)
Calculate the proportion of each stratum in the total population. For
example, if the town's population is 5 lakhs, then 15% are Muslims, 20% are
Sikhs, 10% are Jains, and 55% are Hindus.
(c)
Determine the sample size for each stratum by multiplying the proportion
of the stratum by the desired overall sample size. For instance, if you want a total
sample size of 1,000 households, the sample size for Muslims would be 0.15 *
1000 = 150 households, for Sikhs 0.20 * 1000 = 200 households, and so on.
(d)
Use a random sampling method (such as random number generators)
within each stratum to select the specified number of households. This ensures
that the sample is representative of each religious group's preferences.
Question 3: Suggest the possible sample size that should be taken out from each
community and why?
Answer:
The sample size for each community should be based on the
proportionate allocation method described above. In this case, the sample sizes for
each community would be:
(a)
Muslim - 150 households
(b)
Sikhs - 200 households
(c)
Jains - 100 households
(d)
Hindus - 550 households
This allocation ensures that the sample is proportional to the size of each
community in the population, allowing for more accurate estimates of eating preferences
within each group while maintaining overall representation.